Mitsubishi Melsec-Q Series User Manual page 294

11.4 When Programmable Controller Has Been Stored Without Bat-
tery
When resuming operation of the programmable controller after having been stored without battery installed, the data in
the CPU module and the memory card may be corrupted.
Before restarting operation, format the CPU module memory and SRAM card using GX Developer.
After formatting the memories, write backed up data to each memory.
To format a program memory during boot operation, select the "Clear program memory" checkbox in the Boot file tab
of the PLC parameter dialog box.
Remark
For the Universal model QCPU, when the latch data backup function (to standard ROM) is used, data will not be disap-
peared even if storing data without a battery, since latch data such as device data of the CPU module or error history can
be backed up without using a battery.
The relationships between battery and battery-backed memorie are shown in Table11.15.
CPU module
*3
Memory card
*1: Q6BAT, Q7BAT and Q8BAT are available.
*2: The Universal model QCPU needs no battery backup.
*3: Not applicable the Basic model QCPU.
Before restarting the operation, format the battery-backed memories shown in Table11.15 using GX Developer.
For formatiing memories, refer to the following.
GX Developer Operating Manual
●
Before storing the programmable controller, back up all the data stored in the memories.
●
When the programmable controller is powered on or the CPU module is reset, the CPU module initializes all of the fol-
lowing data if an error is detected.
• Program memory data
• Standard RAM data
• Error history
• Latch data (latch relay (L), devices in latch setting range set in the parameter, special relay SM900 to SM999, spe-
cial register SD900 to SD900)
• Sampling trace data
11 - 34
Table11.15 Relationships between the battery and battery-backed memories
Memory
Program memory
Standard RAM
Standard ROM
SRAM card
Flash card
ATA card
Battery of QCPU Module
*2
---- (Battery backup not needed)
---- (Battery backup not needed)
---- (Battery backup not needed)
: Battery backed up,
Battery
Battery Built in Memory
*1
Card
: Not battery backed up